File Type Checker
Overview
The file type checker helps to enforce security by checking for malicious or unauthorised file types when attachment is uploaded.
What happens when denied attachment is detected?
When File Type Checker detects an attachment that is not allowed based on the configuration, a comment will be added in the corresponding issue to inform the uploader.
The message is configurable and uploader will also be mentioned in the comment.

What should user do when they receive comment notification?
Users should review and delete the mentioned attachment.
If it is really a valid file type needed, it is possible to reach out to the Jira admins to include the file type.
How to configure the list of authorised file extensions?
Please refer to how to configure the File Type Checker for Jira Cloud.